As a general V-path ultrasonic fluid-measuring apparatus, an apparatus is known in which a channel member is accommodated in an accommodating section of a measuring channel, and a first ultrasonic wave measuring section and a second ultrasonic wave measuring section are provided adjacent to each other in the channel member.
That is, as the channel member is formed in a square tube shape by a first side wall part, a second side wall part, a top plate part, and a bottom plate part, a fluid channel (hereinafter referred to as a “channel”) is formed by the channel member. A first ultrasonic wave output section and a second ultrasonic wave output section are provided adjacent to each other in the first side wall part, and the first ultrasonic wave output section and the second ultrasonic wave output section are arranged so as to face the channel.
Additionally, the second side wall part is provided with a reflecting surface, and the reflecting surface is arranged so as to face the channel (for example, refer to Patent Literature 1).